This case study reports on the professional identity development of a group of beginning in-service teacher educators in Türkiye. The focus was on investigating how a group of in-service teacher educators' participation in professional communities and their collaboration with experienced educators and teachers affected their professional identity development. Within the qualitative constructivist paradigm, twelve participants were interviewed for unearthing the social and relational dimensions of developing as teacher educators in Turkish in-service teacher education (INSET) context. The analysis drew on the theoretical-methodological framework which is composed of five identity lenses (becoming, doing, knowing, being, and belonging). The findings indicated that a supportive community of colleagues and the attitudes of INSET participants were the building blocks of teacher educators' development. This article highlights the significance of professional collaboration and the crucial influence of INSET participants on in-service teacher educators' identity development.